Northern Ireland manager Nigel Worthington has warned his players he will have no hesitation in punishing those who step out of line on the pitch.

Worthington delivered his message ahead the Euro 2012 qualifier against World Cup finalists Slovenia on Friday. He was irritated at both Kyle Lafferty and Martin Paterson for picking up yellow cards in the defeat by Montenegro in a friendly last month.

Lafferty was later sent off for Rangers and has never been far from controversy during his time in Scotland. Worthington called the squad together for a pep talk and then explained: "It was straightforward, black and white. Behave yourself on the pitch and off the pitch and I am very happy. If you don't, I will take action, simple as that."

He added: "Maybe they dropped their guard a little bit (in Montenegro), relaxed a little bit and thought, 'Well, I'll have a moan rather than getting on with the game'. That's not how we work."

Worthington believes the players will heed his instructions.

He said: "They have been terrific, they are a great group to work with and I will stand with them through thick and thin.

"I've had the pleasure of playing for and managing the country, that gives you great pride. When I turn up I'm like a baby with a new toy and sometimes too enthusiastic for the players.

"They are doing it every day whereas I am in three or four days every four or five weeks, so I want to get as much coaching in as possible.

"You've got to have the enthusiasm, the drive. I'm the leader of the team, I've got to set the mantle for them."